declare function estimateTotalTokens(messages: any[]): number;
/**
 * If total exceeds threshold, return a new array where the first N
 * messages are collapsed into a single summary.
 * The summarization itself is delegated to the caller (e.g. via sub-agent).
 */
declare function shouldSummarize(messages: any[], model: string, thresholdPct?: number): boolean;
/** Create a plain-text summary of older messages for compression. */
declare function summaryPrompt(olderMessages: any[]): string;

export { estimateTotalTokens, shouldSummarize, summaryPrompt };